Hi Malcolm, too much pressure on primary was one of the first things I checked out. The truth of the matter is I bought cheap, too cheap! the whole set cost about $100 including postage. They look professional but there cheap. $339 for a single eyepiece is out of my price range but I'm happy to pay a fair price for a pre loved eyepiece if it falls in my lap. My problem is I don't know what I'm buying..the techno-bull doesn't mean a thing. Maybe one-day I could send you my set for you to compare? Sadly I'm along way from the main populous to setup next someone to compare optics.
